The UV spectra of three different conformers of the guanine/cytosine base pair were recorded recently with UV-IR double-resonance techniques in a supersonic jet [Abo-Riziq, A., Grace, L., Nir, E., Kabelac, M., Hobza, P. & de Vries, M. S. (2005) Proc. Natl. Acad. Sci. USA 102, 20-23]. The spectra provide evidence for a very efficient excited-state deactivation mechanism that is specific for the ...

These experiments and complementary electronic structure calculations seek to probe the early dissociation dynamics of N2O4 excited in the strong 186 nm ultraviolet absorption band. Laser photons of 199.7, 203, and 205 nm are used to dissociate N2O4 molecules expanded in a free jet. The emission from the dissociating molecules is dispersed in a spectrometer and collected with an optical multich...

We report the fluorescence emission which is driven by femtosecond laser pulses with a repetition rate of 100 MHz and center wavelength 1040 nm in nitrogen gas jet. The experiment performed enhancement cavity coupled high laser. In contrast to previous observation at low jet, where 391-nm radiation was observed but 337-nm missing, three times stronger than our experiment. By examining dependenc...

the applications of electrochemical machining are increasing because of increasing requests of industries for materials with high strengh and high hardness. regular ecm uses a tool with spicified profile shape that is similar to final shape of workpiece. in this reasearch a nozzle that delivers electrolyte to the machining gap is used for machining cylinderical workpieces. by moving the electro...

A study of the electronic spectrum of the gallium dimer in the 33600 – 36800 cm –1 spectral range is presented. The dimer was prepared in a pulsed, free-jet supersonic beam and detected by laser fluorescence excitation and depletion spectroscopy. All observed excited vibronic levels predissociate, and the transitions were detected by observation of Ga 5s AE 4p atomic emission. Four excited-stat...

We report vibrational information of both the first electronically excited state and the ground cationic state of jet-cooled triphenylene via the techniques of resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The first excited electronic state S1 of the neutral molecule is of A1' symmetry and is therefore electric dipole forbidden in ...

The cis<-->trans isomerization reaction has been carried out for 2-naphthol and its hydrogen (H) bonded clusters by infrared (IR) laser in the electronic excited state (S1) in supersonic jets. A specific isomer in the jet was pumped to the X-H stretching vibration in the S1 state, where X refers to C, O, or N atom, by using a stepwise UV-IR excitation, and the dispersed emission spectra of the ...

An experiment of He gas-contact for generating population inversion in a recombining Ar plasma jet is carried out. Population inversion between Ar I excited states 5s′ → 4p′[1/2]1 and 5s′ → 4p[3/2]1,2, [5/2]2,3 is created by helium gas-contact cooling of electrons, whereas it is not created without gas-contact. Ar I lines 1.14 μm, 1.34 μm, and 1.09 μm are strongly enhnced due to the He gas cool...